ARTICLE Maternal Autoimmune Diseases, Asthma and Allergies, and Childhood Autism Spectrum D.pdf

ARTICLE Maternal Autoimmune Diseases, Asthma and Allergies, and Childhood Autism Spectrum Disorders A Case-control Study Lisa A. Croen, PhD; Judith K. Grether, PhD; Cathleen K. Yoshida, MS; Roxana Odouli, MSPH; Judy Van de Water, PhD Objective: To investigate the association between phy- sician-documented diagnoses of maternal autoimmune diseases, allergies, and asthma around the time of preg- nancy and subsequent diagnoses of autism in children. Design: A case-control study nested within a cohort of infants born between January 1995 and June 1999. Setting: Northern California Kaiser Permanente Medi- cal Care Program. Participants: Cases (n=420) were children with at least 1 diagnosis of an autism spectrum disorder (ASD) re- corded in Kaiser Permanente outpatient clinical data- bases. Controls (n=2100) were children without an ASD diagnosis who were frequency matched to cases on sex, birth year, and hospital of birth. Main Outcome Measures: Frequencies of maternal immunologic disorders were compared between cases and controls with a
2 statistic, and relative risks were esti- mated by crude and adjusted odds ratios and 95% con- fidence intervals using logistic regression. Results: The final study population included 407 cases and 2095 controls. A similar proportion of case and con- trol mothers had a diagnosis of any autoimmune dis- ease in the 4-year period surrounding pregnancy (10.3% vs 8.2%, P=.15). After adjustment for maternal factors, only 1 autoimmune condition, psoriasis, was signifi- cantly associated with ASDs (adjusted odds ratio, 2.7; 95% confidence interval, 1.3-5.8). A greater than 2-fold el- evated risk of ASD was observed for maternal asthma and allergy diagnoses recorded during the second trimester of pregnancy. Conclusions: These findings suggest that maternal au- toimmune disorders present in women around the time of pregnancy are unlikely to contribute significantly to autism risk. Further etiologic investigations are needed to confirm these res